LIGO Document P1100029-v36

All-sky Search for Periodic Gravitational Waves in the Full S5 LIGO Data

We report on an all-sky search for periodic gravitational waves in the frequency band 50-800 Hz and with the frequency time derivative in the range of 0 through -6 x 10^-9 Hz/s. After recent improvements in the search program that yielded a 10x increase in computational efficiency, we have searched in two years of data collected during LIGO's fifth science run and have obtained the most sensitive all-sky upper limits on gravitational wave strain to date. Near 150 Hz our upper limit on worst-case linearly polarized strain amplitude h0 is 1 x 10^-24, while at the high end of our frequency range we achieve a worst-case upper limit of 3.8 x 10^-24 for all polarizations and sky locations. These results constitute a factor of two improvement upon previously published data. New detection pipeline utilizing loosely coherent algorithm was able to follow up weaker outliers increasing detection volume by a factor of 10, but have not revealed any gravitational wave signals.